Send Split Info Callback before Activity#onCreate

The onTaskFragmentInfo callback from the server
triggered by the creation of a new activity may not
reach the client before Activity#onCreate is called
because of undeterministic IPC call order. However, the
application should get a split info update that includes
the newly launched activity before the Activity#onCreate
is called for that activity so that the application
knows that the activity will be in a split, which may
influence UI decisions.

Bug: b/218791665 b/200303250
Test: atest ActivityEmbeddingLaunchTests
Change-Id: If69c077db8ca390d41446e1329a448b3dd074293

3 files changed, 42 insertions, 4 deletions

diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
index 418ff0e7263a..c7d62530a43d 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
@@ -602,14 +602,22 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
         return null;
     }
 
+    private void updateCallbackIfNecessary() {
+        updateCallbackIfNecessary(true /* deferCallbackUntilAllActivitiesCreated */);
+    }
+
     /**
      * Notifies listeners about changes to split states if necessary.
+     *
+     * @param deferCallbackUntilAllActivitiesCreated boolean to indicate whether the split info
+     *                                               callback should be deferred until all the
+     *                                               organized activities have been created.
      */
-    private void updateCallbackIfNecessary() {
+    private void updateCallbackIfNecessary(boolean deferCallbackUntilAllActivitiesCreated) {
         if (mEmbeddingCallback == null) {
             return;
         }
-        if (!allActivitiesCreated()) {
+        if (deferCallbackUntilAllActivitiesCreated && !allActivitiesCreated()) {
             return;
         }
         List<SplitInfo> currentSplitStates = getActiveSplitStates();
@@ -825,6 +833,36 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
     private final class LifecycleCallbacks extends EmptyLifecycleCallbacksAdapter {
 
         @Override
+        public void onActivityPreCreated(Activity activity, Bundle savedInstanceState) {
+            final IBinder activityToken = activity.getActivityToken();
+            final IBinder initialTaskFragmentToken = ActivityThread.currentActivityThread()
+                    .getActivityClient(activityToken).mInitialTaskFragmentToken;
+            // If the activity is not embedded, then it will not have an initial task fragment token
+            // so no further action is needed.
+            if (initialTaskFragmentToken == null) {
+                return;
+            }
+            for (int i = mTaskContainers.size() - 1; i >= 0; i--) {
+                final List<TaskFragmentContainer> containers = mTaskContainers.valueAt(i)
+                        .mContainers;
+                for (int j = containers.size() - 1; j >= 0; j--) {
+                    final TaskFragmentContainer container = containers.get(j);
+                    if (!container.hasActivity(activityToken)
+                            && container.getTaskFragmentToken().equals(initialTaskFragmentToken)) {
+                        // The onTaskFragmentInfoChanged callback containing this activity has not
+                        // reached the client yet, so add the activity to the pending appeared
+                        // activities and send a split info callback to the client before
+                        // {@link Activity#onCreate} is called.
+                        container.addPendingAppearedActivity(activity);
+                        updateCallbackIfNecessary(
+                                false /* deferCallbackUntilAllActivitiesCreated */);
+                        return;
+                    }
+                }
+            }
+        }
+
+        @Override
         public void onActivityPostCreated(Activity activity, Bundle savedInstanceState) {
             // Calling after Activity#onCreate is complete to allow the app launch something
             // first. In case of a configured placeholder activity we want to make sure
diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java
index e49af41d4eac..9a12669f078a 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java
@@ -120,7 +120,7 @@ class TaskFragmentContainer {
     }
 
     ActivityStack toActivityStack() {
-        return new ActivityStack(collectActivities(), mInfo.getRunningActivityCount() == 0);
+        return new ActivityStack(collectActivities(), isEmpty());
     }
 
     void addPendingAppearedActivity(@NonNull Activity pendingAppearedActivity) {
diff --git a/services/core/java/com/android/server/wm/TaskFragment.java b/services/core/java/com/android/server/wm/TaskFragment.java
index 23df429c3f24..cf32457211af 100644
--- a/services/core/java/com/android/server/wm/TaskFragment.java
+++ b/services/core/java/com/android/server/wm/TaskFragment.java
@@ -2264,7 +2264,7 @@ class TaskFragment extends WindowContainer<WindowContainer> {
                 mFragmentToken,
                 mRemoteToken.toWindowContainerToken(),
                 getConfiguration(),
-                getChildCount() == 0,
+                runningActivityCount[0] == 0,
                 runningActivityCount[0],
                 isVisible(),
                 childActivities,